P1653: CLINICAL EFFICACY AND SAFETY OF SWITCHING ELTROMBOPAG AND RH-TPO IN PATIENTS WITH IMMUNE THROMBOCYTOPENIA DURING THE COVID-19 PANDEMIC
Authors: X. Cai, X.-H. Zhang
Journal: HemaSphere (2022)

Background: The current COVID-19 pandemic poses several dilemmas for the management of immune thrombocytopenia (ITP). Patients taking immunosuppressive agents have been considered potentially at risk for severe acute respiratory syndrome coronavirus 2 infection. In addition, clinical studies have reported significantly higher fatality rates and more severe complications in COVID-19 patients on immunosuppressive therapy (Lancet, 2020). Thus, a new prescription or increase in dose of an immunosuppressant is not proposed for ITP patients (Br J Haematol, 2020). Recommendations have been made that nonimmunosuppressive treatments, such as thrombopoietin (TPO) agents, be the first choice for ITP during the COVID-19 pandemic (ASH, 2020). The recombinant human TPO (rh-TPO) and eltrombopag are two distinct TPO receptor agonists (TPO-RAs) with different treatment mechanisms, side effects and administration routes. Based on previous clinical evidence, switching from one TPO-RA to another provides favorable outcomes. Aims: Therefore, we proposed a prospective observational study to evaluate the response and safety of switching between eltrombopag and rh-TPO in adult ITP patients during the pandemic for the first time. Methods: Adult ITP patients who received rh-TPO and then needed to switch to eltrombopag or vice versa were screened for eligibility. After enrollment, patients were followed up prospectively on administering the second TPO-RA. Results: Between January 2020 and January 2021 at Peking University People’s Hospital, 53 patients switching from rh-TPO to eltrombopag and 43 patients switching from eltrombopag to rh-TPO were enrolled in our study after screen. Overall, 61/96 patients (63.5%) achieved a response at 6 months after switch. The outcomes were comparable regardless of the direction of the switch. Response rates at six months after switch (the primary endpoint) varied significantly among patients in different clinical settings (Figure 2). In the inefficacy group, 13 of 27 patients (48%) responded to eltrombopag, and 11 of 22 patients (50%) responded to rh-TPO at 6 months after switch. In the non-efficacy-related group, 85% and 71% of patients in eltrombopag and rh-TPO group maintained their response rates, respectively. The primary outcomes were comparable between eltrombopag and rh-TPO group. In the inefficacy group, there were no differences in the secondary outcomes of platelet counts, time to response, duration of response and bleeding events after switch between eltrombopag and rh-TPO group. In the non-efficacy-related group, the increase of the platelet counts after switch were also comparable between eltrombopag and rh-TPO group. Similar to the platelet counts, the response rates at 6 months, time to response, duration of response and incidence of bleeding after switch were also comparable between the 2 groups. A total of 13 patients underwent switch due to side effects, and most of these patients had their adverse events resolved during treatment with the second TPO-RA. Both after-switch treatments were well tolerated and adverse events were all grade 1–2 in severity. None of these patients were diagnosed with COVID-19 infection during the follow-up period. We did not identify any risk factor that could predict better outcomes at 6 months after switch. Image:Summary/Conclusion: In the current COVID-19 pandemic, our study demonstrated the efficacy and safety of switching between eltrombopag and rh-TPO as treatments for ITP. Thus, switching to the alternate TPO-RA may be a desirable option in patients refractory or intolerable to their first TPO-RA.